(1) Field of the Invention
The invention relates to a method of removing polymer buildup on a wafer and on the etch chamber walls in the manufacture of integrated circuits, and more particularly, to a method of removing polymer buildup after spin-on-glass etchback in the manufacture of integrated circuits.
(2) Description of the Prior Art
In the current sub-micron technology of the manufacture of integrated circuit devices, the spin-on-glass etchback process has been adopted widely to improve planarization. However, spin-on-glass etchback causes the buildup of polymer on the upper electrode and the chamber wall of the etch chamber. The polymer buildup on the electrode results in an unstable etch rate and non-uniformity.
U.S. Pat. No. 5,679,211 to Huang discloses an oxygen-containing plasma treatment to remove a polymer formed on a spin-on-glass layer by the process of etching the spin-on-glass layer. U.S. Pat. No. 5,639,345 to Huang et al teaches a two-step SOG etchback process. These processes address polymer buildup on the wafer rather than the problem of polymer buildup in the etch chamber.
Accordingly, a principal object of the present invention is to provide an effective and very manufacturable method of removing polymer buildup from an etch chamber.
A further object of the invention is to provide a method for removing polymer buildup from the upper electrode and walls of an etch chamber after spin-on-glass etchback.
A still further object of the invention is to provide a method for removing polymer buildup from the upper electrode and walls of an etch chamber after spin-on-glass etchback to improve the etch rate and etch uniformity.
Yet another object is to provide a method for improving particle level, stability of etch rate, and etch uniformity by removing polymer buildup from the upper electrode and walls of an etch chamber after spin-on-glass etchback.
Yet another object of the invention is to provide a method for improving particle level, stability of etch rate, and etch uniformity by using a dry plasma clean to remove polymer buildup from the upper electrode and walls of an etch chamber after spin-on-glass etchback.
In accordance with the objects of this invention a new method for improving particle level, stability of etch rate, and etch uniformity by using a dry plasma clean to remove polymer buildup from the upper electrode and walls of an etch chamber after spin-on-glass etchback is achieved. An etching chamber having a lower electrode, upper electrode, and interior walls is provided. Spin-on-glass etchback is performed within the etching chamber whereby a polymer buildup forms on surfaces of the chamber. A dummy wafer is placed into the etching chamber and the polymer buildup within the chamber is removed using a dry plasma cleaning process.